Like some others, I won't say what I 'd do hypothetically but what I did actually do: I got the M262.
I'd been eyeing the M9 for FF, (count me in the 'not-a-fan-of-cropped-sensors-because-i-still-mostly-shoot-film' camp) still wasn't jazzed with low light performance or the surprisingly high resell price. Left the M240 and M262. I was finding the latter in better condition for a lot lower prices, despite being a nominally newer camera. I guess people will really pay a premium for LV and a frame line preview lever.
But I really don't mind buying used and dinged gear, so more of a factor was the rumored better lowlight of the 262
: supposedly same sensor, but different signal processing. No, it's still not A7-levels of performance, but hey, I'm shooting an M for a reason, and I'd rather trade mediocre live view for it, since after dark is when switch film for silicon. A nice minty camera was a plus.
My thoughts on LV: I don't use it, or want it, at all. Used to use a Nikon D3s for work and it came in handy for unusual shots, but it was an otherwise atrocious experience; same went with the X100 EVF. From what I understand, the 240 wasn't that much better. Even on modern cameras I've played with in person, I still prefer an optical finder. I'll admit some curiosity, since I'd love to see what some of my Bronica lenses look like on digital, but eh. Wasn't worth it. But that's just my personal usage...if I had a lot more vintage SLR lenses, I might be more inclined.